Is Preston Lake Safe for Swimming?
Preston Lake in Renville County, Minnesota has a water quality grade of F (Very Poor). Avoid swimming, very poor water quality, potential algae toxins. Water clarity: 5 ft visibility. Phosphorus: 222 µg/L. Chlorophyll-a (algae): 44.1 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | F (Very Poor) |
| Water Clarity (Secchi Depth) | 5 ft |
| Phosphorus | 222 μg/L |
| Chlorophyll-a (Algae) | 44.1 μg/L |
| Maximum Depth | 11 ft |
| Location | Renville County, Minnesota |
How does Preston Lake compare?
With an overall water quality grade of F, Preston Lake falls below the Minnesota state average of Grade C. It ranks #1 of 2 lakes in Renville County by water quality score.
Water clarity (Secchi depth) sits at 5 feet. That falls into moderate clarity — typical for lakes with some nutrient enrichment. Algae levels (chlorophyll-a) measure 44.1 µg/L — elevated; risk of harmful algal bloom advisories increases at this concentration.